In a little over two weeks, more than 3,000 billion liters of water recently flooded out of an ice-dammed lake in East Greenland. It’s the first time scientists have closely documented such an event and their insights could help to uncover how outburst flooding could wreak havoc elsewhere in the world.
The incident unfolded earlier this year between September 23 and October 11 at Greenland’s Catalina Lake, a proglacial lake that’s situated in a valley blocked by the massive Edward Bailey Glacier.
Water has been accumulating in the lake over the past 20 years, but it recently reached a critical point, causing the glacier to lift up. A 25-kilometer (15.5-mile) long tunnel was naturally carved beneath the ice, transporting a gigantic amount of lake water toward the world’s largest fjord, Scoresby Sound. Back at Catalina Lake, water levels plummeted by 154 meters (505 feet).
All of this was watched closely in real-time using satellite imagery by scientists from the University of Copenhagen’s Niels Bohr Institute.
“In this case, the energy released by the glacier flood was equivalent to the output of the world’s largest nuclear power plant running at full capacity for 22 days,” Aslak Grinsted, a climate researcher at the Niels Bohr Institute, said in a statement.
The event is what’s known as a glacial lake outburst flood (GLOF). As this instance shows, the breakdown of an ice-dammed lake can be triggered by natural causes, including the buildup of water, erosion, heavy snow or rain, earthquakes, and volcanic eruptions.
GLOF events can also be sparked by human-driven climate change, caused by thawing glaciers in the wake of rising temperatures.
“The danger from glacier-dammed lakes is increasing due to global warming. It’s vital to improve our understanding of this phenomenon to issue timely warnings should there be an imminent risk,” explained Grinsted.
The latest flooding in East Greenland was fortunate in the sense that the surrounding region is sparsely populated, so the risk to humans was minimal. However, there are plenty of proglacial lakes in the world that loom over highly populated areas. A 2023 study concluded that 15 million people across the world are at risk of deadly glacial floods, primarily in India, Pakistan, Peru, and China.
“I expect that we will witness outbursts from even larger ice-dammed lakes as Greenland’s ice sheet retreats in coming centuries. At the end of the last Ice Age, Lake Missoula had an outburst that was 2,500 times larger than the recent Catalina event. To understand these massive forces, we must study the largest outbursts when they occur,” added Grinsted.
It isn’t all pessimistic, though. The researchers point out that the immense amount of energy released by GLOFs has raised the prospect of exploring the outbursts as a source of green energy. The energy recently released from the Catalina Lake event could have continuously provided 50 megawatts of electricity, enough to meet the needs of a small town. It wouldn’t be easy to build the infrastructure necessary to harness the power in a place like Greenland, but it’s a tantalizing idea.
“As with many other natural resources in Greenland, infrastructure is a problem. But if a brilliant engineer could figure out how to harness these meltwater outbursts, there’s enormous power and energy potential in them,” concludes Grinsted.
Source Link: Over 3,000 Billion Liters Of Water Flooded Out Of A Glacial Lake In Just 18 Days
